The present invention relates to an art of laminating a thin film, and particularly relates to an art effectively applicable to a lamination art in which a cutter is moved across the direction of feed of a continuous thin film so that the thin film is cut off to a prescribed size; and the thin film cut off to the prescribed size is laminated on a substrate.
Printed circuit boards used in electronic equipment such as a computers are formed by depositing a predetermined pattern of wires cf conductive materials such as copper on one or both sides of an insulating substrate.
Printed circuit boards of this type can be manufactured by the following process.
First, an assembly of a photosensitive resin layer (photoresist) and a transparent resin layer (protective film) is laminated over an electro-conductive layer on the insulating substrate by thermo-compression. This step is commercially carried out with a device called a laminator. Thereafter, a film with a wiring pattern is superposed on the assembly and the photosensitive resin layer is exposed to light for a predetermined period of time through the patterned film and the transparent resin film. Subsequently, the transparent resin film is stripped with a peeler and the exposed photosensitive resin layer is developed to form a mask pattern for etching.
A laminator, which is used in a process of manufacturing a printed circuit board, is constructed so as to automatically laminate a stacked assembly by heat and pressure.
A conventional laminator disclosed in U.S. Pat. No. 4,585,509 made by the present applicant performs lamination by heat and pressure as described from now on. A stacked assembly continuously wound on the feed roller of the laminator is fed to a substrate by using a main vacuum attraction or absorption plate which has a plurality of suctional attraction or absorption holes in the stacked assembly feed side of the main vacuum attraction plate so that the stacked assembly is attracted on the suctional attraction holes by suction and fed to the substrate. The leading edge of the stacked assembly fed to the substrate is tentatively stuck to an electroconductive layer on the electrically-insulating substrate by heat and pressure through the use of an arc-shaped tentative sticking portion provided at the downstream end of the main vacuum attraction plate with regard to the direction of feed of the stacked assembly The leading edge of the stacked assembly is attracted to the tentative sticking portion through the use of an auxiliary vacuum attraction plate which is moved toward and away from the passage for the feed of the stacked assembly The stacked assembly whose leading edge is tentatively stuck to the electroconductive layer on the electrically insulating substrate is laminated on the substrate by heat and pressure through the use of a heat and pressure sticking roller After the stacked assembly is laminated by a prescribed quantity on the substrate, the stacked assembly is cut off, by a cutter unit, to a prescribed size corresponding to the substrate. The cutter unit has a disk-shaped cutter which is moved across the direction of feed of the stacked assembly so as to cut off the stacked assembly The disk-shaped cutter is supported by a moving member coupled to the moving portion of an air cylinder of the rodless type The trailing edge of the stacked assembly is finally stuck to the substrate by the heat and pressure sticking rollers.
It is desired that the speed of the heat and pressure lamination of the stacked assembly by the above-mentioned conventional laminator is increased to enhance the printed circuit board production capacity of the laminator. In order to increase the speed of the heat and pressure lamination of the stacked assembly, the speed of the feed of the stacked assembly, that of the cutoff of the stacked assembly and that of the heat and pressure lamination of the stacked assembly need to be heightened. Since the cut-off position of the stacked assembly needs to be substantially put at a standstill in the direction of feed thereof when the cutter is moved to cut off the stacked assembly, the speed of the movement of the cutter is considerably increased. For that reason, the cutter unit is vibrated and the laminator is vibrated through the cutter unit when the cutter is halted in a stopped position after the stacked assembly is cut off by moving the cutter.
Conducting an experiment and studying the result thereof, the present inventors have found out that the above-mentioned vibration takes place because of the collision of the end of the moving portion of the air cylinder of the cutter unit against the inside end of the cylinder. Although air for moving the moving portion of the air cylinder is slightly left at the inside end of the air cylinder so as to act as a buffer to reduce the vibration, the collision of the moving portion against the inside end of the air cylinder cannot be prevented by the small amount of air in the air cylinder when the speed of the movement of the moving portion is increased, namely, when the speed of the movement of the cutter is increased. The vibration of the cutter unit or the laminator brings on a problem which is the loosening of the screw of a joint, the shortening of the life of the laminator, the increase in the labor for maintenance work or the like.